scholarly journals Chloramphenicol Resurrected: A Journey from Antibiotic Resistance in Eye Infections to Biofilm and Ocular Microbiota

2019 ◽  
Vol 7 (9) ◽  
pp. 278 ◽  
Author(s):  
Lorenzo
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
In Vivo Studies ◽  
Antibiofilm Activity ◽  
Eye Infections ◽  
Treatment And Prevention ◽  
Old Drugs

The advent of multidrug resistance among pathogenic bacteria is devastating the worth of antibiotics and changing the way of their administration, as well as the approach to use new or old drugs. The crisis of antimicrobial resistance is also due to the unavailability of newer drugs, attributable to exigent regulatory requirements and reduced financial inducements. The emerging resistance to antibiotics worldwide has led to renewed interest in old drugs that have fallen into disuse because of toxic side effects. Thus, comprehensive efforts are needed to minimize the pace of resistance by studying emergent microorganisms and optimize the use of old antimicrobial agents able to maintain their profile of susceptibility. Chloramphenicol is experiencing its renaissance because it is widely used in the treatment and prevention of superficial eye infections due to its broad spectrum of activity and other useful antimicrobial peculiarities, such as the antibiofilm properties. Concerns have been raised in the past for the risk of aplastic anemia when chloramphenicol is given intravenously. Chloramphenicol seems suitable to be used as topical eye formulation for the limited rate of resistance compared to fluoroquinolones, for its scarce induction of bacterial resistance and antibiofilm activity, and for the hypothetical low impact on ocular microbiota disturbance. Further in-vitro and in vivo studies on pharmacodynamics properties of ocular formulation of chloramphenicol, as well as its real impact against biofilm and the ocular microbiota, need to be better addressed in the near future.

scholarly journals Antimicrobial Activity from Species Plectranthus amboinicus (Lour.) Spreng, a Review

2020 ◽  
pp. 1-14
Author(s):  
Juliane Maria dos Santos Silva ◽  
Jackson Roberto Guedes da Silva Almeida ◽  
Cristiane dos Santos Cerqueira Alves ◽  
Daniel Amando Nery ◽  
Livia Maria Oliveira Damasceno ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Therapeutic Potential ◽  
In Vivo Studies ◽  
Synergistic Activity ◽  
Popular Medicine ◽  
Plectranthus Amboinicus

Introduction: Nowadays, several bacteria have acquired resistance to available antimicrobial agents making necessary the search for new therapeutic alternatives. Plectranthus amboinicus L. is a succulent and aromatic herb, popularly known as thick leaf mint, used in popular medicine for the treatment of colds, digestive diseases, asthma, headache and to fight pathogenic bacteria activity. In view the antimicrobial activity of P. amboinicus this study had as aim to review publications involving researches about antimicrobial activity of this species. Materials and Methods: For this, PubMed, Scopus, Science Direct and Scielo databases were consulted in November 2020 using the keywords Plectranthus amboinicus and antimicrobial activity. In vitro and/or in vivo studies on the antimicrobial activity of the species in the last 10 years were considered. Results: The main microorganisms evaluated were: Klebsiella pneumoniae, Mycobacterium tuberculosis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and some Candida species. The essential oils had carvacrol, germacrene D, thymol and camphor as main constituents. Most studies evaluated the antimicrobial activity using broth dilution and agar diffusion methods. In most studies essential oil, extracts and/or isolated substances showed significant antimicrobial activity. Synergistic activity was also observed through association with antibiotics. Conclusion: P. amboinicus has therapeutic potential for antimicrobial treatments and can be an alternative to the treatment of resistant microorganisms and that further in vivo and clinical studies with the species are still needed.

Therapeutic Potential of Biofilm-Dispersing Enzymes

2009 ◽  
Vol 32 (9) ◽  
pp. 545-554 ◽  
Author(s):  
Jeffrey B. Kaplan
Keyword(s):  
Antimicrobial Agents ◽  
Therapeutic Potential ◽  
Film Formation ◽  
In Vivo Studies ◽  
Bacterial Cells ◽  
Deoxyribonuclease I ◽  
Treatment And Prevention ◽  
Biofilm Matrix

Surface-attached colonies of bacteria known as biofilms play a major role in the pathogenesis of medical device infections. Biofilm colonies are notorious for their resistance to antibiotics and host defenses, which makes most device infections difficult or impossible to eradicate. Bacterial cells in a biofilm are held together by an extracellular polymeric matrix that is synthesized by the bacteria themselves. Enzymes that degrade biofilm matrix polymers have been shown to inhibit bio film formation, detach established bio film colonies, and render biofilm cells sensitive to killing by antimicrobial agents. This review discusses the potential use of biofilm matrix-degrading enzymes as anti-biofilm agents for the treatment and prevention of device infections. Two enzymes, deoxyribonuclease I and the glycoside hydrolase dispersin B, will be reviewed in detail. In vitro and in vivo studies demonstrating the anti-biofilm activities of these two enzymes will be summarized, and the therapeutic potential and possible drawbacks of using these enzymes as clinical agents will be discussed.

scholarly journals Antibacterial Mechanisms and Efficacy of Sarecycline in Animal Models of Infection and Inflammation

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 439
Author(s):  
Christopher G. Bunick ◽  
Jonette Keri ◽  
S. Ken Tanaka ◽  
Nika Furey ◽  
Giovanni Damiani ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Bacterial Resistance ◽  
Antibiotic Use ◽  
In Vivo Studies ◽  
Infection Model ◽  
Severe Acne ◽  
Rat Paw Edema ◽  
Infection And Inflammation

Prolonged broad-spectrum antibiotic use is more likely to induce bacterial resistance and dysbiosis of skin and gut microflora. First and second-generation tetracycline-class antibiotics have similar broad-spectrum antibacterial activity. Targeted tetracycline-class antibiotics are needed to limit antimicrobial resistance and improve patient outcomes. Sarecycline is a narrow-spectrum, third-generation tetracycline-class antibiotic Food and Drug Administration (FDA)-approved for treating moderate-to-severe acne. In vitro studies demonstrated activity against clinically relevant Gram-positive bacteria but reduced activity against Gram-negative bacteria. Recent studies have provided insight into how the structure of sarecycline, with a unique C7 moiety, interacts with bacterial ribosomes to block translation and prevent antibiotic resistance. Sarecycline reduces Staphylococcus aureus DNA and protein synthesis with limited effects on RNA, lipid, and bacterial wall synthesis. In agreement with in vitro data, sarecycline demonstrated narrower-spectrum in vivo activity in murine models of infection, exhibiting activity against S. aureus, but reduced efficacy against Escherichia coli compared to doxycycline and minocycline. In a murine neutropenic thigh wound infection model, sarecycline was as effective as doxycycline against S. aureus. The anti-inflammatory activity of sarecycline was comparable to doxycycline and minocycline in a rat paw edema model. Here, we review the antibacterial mechanisms of sarecycline and report results of in vivo studies of infection and inflammation.

scholarly journals Study of Antimicrobial, Antioxidant and Cytotoxicity Properties of Selected Plant Extracts for Food Preservative Applications

2021 ◽  
pp. 95-111
Author(s):  
Tania Islam ◽  
Md Nazrul Islam ◽  
Wahidu Zzaman ◽  
Md Morsaline Billah
Keyword(s):  
Pathogenic Bacteria ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
In Vivo Studies ◽  
Diffusion Method ◽  
Plant Materials ◽  
Food Preservative

An attempt has been made to evaluate antimicrobial, antioxidant and cytotoxicity properties of extracts from onion (Allium cepa L.), garlic (Allium sativum), leaves of guava (Psidium guajava), papaya (Carica papaya), tea (Camellia sinensis), baen (Avicennia alba) and keora (Sonneratia apetala), respectively to apply as natural preservatives for tomatoes. The air-dried plant materials of the respective plant species were subjected to ethanol-methanol extraction, concentrated and stored at 4 °C before use. The extracts were dissolved in 95% ethanol for analysis of antioxidant and antimicrobial properties. Of the extracts tested, tea extracts showed the highest zone of inhibition against several pathogenic bacteria (E. coli 35.0±3.2 mm; P. aeruginosa 29.3±2.6 mm; S. typhi 28.4±2.1 mm and S. pyogenes 27.7±3.7 mm) using the disc diffusion method. In regard to DPPH free radical scavenging assay, keora and guava extracts showed the highest percentage of radical scavenging activity with the values of 89.64± 0.18 and 89.39± 0.88, respectively, which were in agreement with higher total antioxidant capacity (TAC) of these extracts obtained by the phosphomolybdenum method. Brine shrimp lethality bioassay for cytotoxicity assessment showed LC50 of 132.54 ± 18.99 µg/mL for the leaf extract of keora which was found to be most toxic among all studied extracts. The initial results indicated that the extracts could be used for food preservative applications based on the antimicrobial, antioxidant and cytotoxicity properties of the tested extracts. However, efficacy, stability and safety issues need to be addressed with both in vitro and in vivo studies.

scholarly journals Antidiabetic Effects of Hydroxytyrosol: In Vitro and In Vivo Evidence

Antioxidants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 188 ◽  
Author(s):  
Filip Vlavcheski ◽  
Mariah Young ◽  
Evangelia Tsiani
Keyword(s):  
Insulin Resistance ◽  
Pathological Condition ◽  
Current Treatment ◽  
In Vivo Studies ◽  
Olive Leaves ◽  
Treatment And Prevention ◽  
Antidiabetic Effects

Insulin resistance, a pathological condition characterized by defects in insulin action leads to the development of Type 2 diabetes mellitus (T2DM), a disease which is currently on the rise that pose an enormous economic burden to healthcare systems worldwide. The current treatment and prevention strategies are considerably lacking in number and efficacy and therefore new targeted therapies and preventative strategies are urgently needed. Plant-derived chemicals such as metformin, derived from the French lilac, have been used to treat/manage insulin resistance and T2DM. Other plant-derived chemicals which are not yet discovered, may have superior properties to prevent and manage T2DM and thus research into this area is highly justifiable. Hydroxytyrosol is a phenolic phytochemical found in olive leaves and olive oil reported to have antioxidant, anti-inflammatory, anticancer and antidiabetic properties. The present review summarizes the current in vitro and in vivo studies examining the antidiabetic properties of hydroxytyrosol and investigating the mechanisms of its action.

scholarly journals Plant Products as Antimicrobial Agents

1999 ◽  
Vol 12 (4) ◽  
pp. 564-582 ◽  
Author(s):  
Marjorie Murphy Cowan
Keyword(s):  
Secondary Metabolites ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Traditional Healers ◽  
In Vivo Studies ◽  
Current Status ◽  
The Public ◽  
The Earth

SUMMARY The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and “leads” which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

scholarly journals Evaluation and Comparison of Antibacterial Efficacy of Herbal Extracts in Combination with Antibiotics on Periodontal pathobionts: An in vitro Microbiological Study

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 89 ◽  
Author(s):  
Shahabe Abullais Saquib ◽  
Nabeeh Abdullah AlQahtani ◽  
Irfan Ahmad ◽  
Mohammed Abdul Kader ◽  
Sami Saeed Al Shahrani ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Plant Extracts ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Synergistic Activity ◽  
Antibacterial Efficacy ◽  
Herbal Extracts ◽  
Inhibition Zones

Background: In the past few decades focus of research has been toward herbal medicines because of growing bacterial resistance and side effects of antimicrobial agents. The extract derived from the plants may increase the efficacy of antibiotics when used in combination against pathogenic bacteria. In the current study, the synergistic antibacterial efficacy of plant extracts in combination with antibiotics has been assessed on selected periodontal pathogens. Methods: Ethanolic extracts were prepared from Salvadora persica (Miswak) and Cinnamomum zeylanicum (Ceylon cinnamon), by the soxhalate method. Plaque samples were collected from clinical periodontitis patients to isolate and grow the periodontal pathobionts under favorable conditions. Susceptibility of bacteria to the extracts was assessed by gauging the diameter of the inhibition zones. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined against each bacterium. Synergistic activity of plants extract in combination with antibiotics against the bacteria was also assessed by measuring the diameter of the inhibition zones. Results: Ethanolic extract of both the plants showed an inhibitory effect on the proliferation and growth of all four strains of periodontal pathobionts. Maximum antibacterial activity was exhibited by C. zeylanicum against Tannerella forsythia (MIC = 1.56 ± 0.24 mg/mL, MBC = 6.25 ± 0.68 mg/mL), whereas among all the studied groups the minimum activity was reported by C. zeylanicum against Aggregatibacter actinomycetemcomitans the (MIC = 12.5 ± 3.25 mg/mL, MBC = 75 ± 8.23 mg/mL). Combination of herbal extracts with different antibiotics revealed a synergistic antibacterial effect. The best synergism was exhibited by S. persica with metronidazole against A. actinomycetemcomitans (27 ± 1.78). Conclusions: Current in vitro study showed variable antibacterial activity by experimented herbal extracts against periodontal pathobionts. The synergistic test showed significant antibacterial activity when plant extracts were combined with antibiotics.

A Practical Look at the Clinical Usefulness of the Beta-Lactam/Beta-Lactamase Inhibitor Combinations

1996 ◽  
Vol 30 (10) ◽  
pp. 1130-1140 ◽  
Author(s):  
Susan M. Hart ◽  
Elaine M. Bailey
Keyword(s):  
English Language ◽  
Antimicrobial Agents ◽  
In Vivo Studies ◽  
Patient Specific ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Intraabdominal Infections ◽  
Lactamase Inhibitor

OBJECTIVE: To aid clinicians in developing an approach to the use of intravenous beta-lactam/beta-lactamase inhibitors on a patient-specific basis. To achieve this, the pharmacology, in vitro activity, and clinical use of the intravenous beta-lactam/beta-lactamase inhibitor combinations in the treatment of selected infections seen in hospitalized patients are discussed. DATA IDENTIFICATION: An English-language literature search using MEDLINE (1987–1995); Index Medicus (1987–1995); program and abstracts of the 32nd (1992), 33rd (1993), 34th (1994), and 35th (1995) Interscience Conference on Antimicrobial Agents and Chemotherapy; bibliographic reviews of review articles; and package inserts. STUDY SELECTION: In vitro and in vivo studies on the pharmacokinetics, microbiology, pharmacology, and clinical effectiveness of ampicillin/sulbactam, ticarcillin/clavulanate, and piperacillin/tazobactam were evaluated. DATA SYNTHESIS: Many properties of the beta-lactam/beta-lactamase inhibitor combinations are similar. Differences in dosing, susceptibilities, and clinical applications are important considerations for clinicians. Potential roles for these agents in the clinical setting include pneumonia, intraabdominal infections, and soft tissue infections. A short discussion on susceptibility data interpretation is also presented. CONCLUSIONS: There are important differences among the available beta-lactam/beta-lactamase inhibitor combinations, such as spectra of activity, which need to be considered in choosing an agent for a patient-specific case. These products can be useful alternatives to conventional two- to three-drug regimens in mixed infections such as foot infections in patients with diabetes and hospital-acquired intraabdominal infections.

scholarly journals Developing an antibiotic effective against multi-drug resistant bacteria.

2014 ◽  
Vol 70 (a1) ◽  
pp. C714-C714
Author(s):  
Calvin Steussy ◽  
Cynthia Stauffacher ◽  
Mark Lipton ◽  
Mohamed Seleem
Keyword(s):  
Pathogenic Bacteria ◽  
Modern Medicine ◽  
In Vivo Studies ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Lead Compound ◽  
Drug Resistant Bacteria ◽  
Coa Reductase

The emergence of multi-drug resistant pathogenic bacteria is one of the great challenges to modern medicine. The gram positive cocci Methicillin Resistant Staphylococcus aureus (MRSA) and Vancomycin Resistant Enterococcus faecalis (VRE) are two particularly virulent examples. In vivo studies have shown that the eukaryotic like 'mevalonate' isoprenoid pathway used by these pathogenic cocci is essential to their growth and virulence [1]. Our structures of HMG-CoA reductase (HMGR) from P. mevalonii demonstrated that the bacterial enzymes are structurally distinct from the human enzymes allowing for specific antibacterial activity [2]. High throughput in vitro screening against bacterial HMGR at the Southern Research Center, Birmingham, AL uncovered a lead compound with an IC50 of 80 µM with a competitive mode of action. Our x-ray crystal structures of HMGR from E. faecalis complexed with the lead compound and its variations have informed the synthesis of new inhibitors that have improved the IC50 to 5 µM [3]. Studies of this compound show it to be active against both MRSA and VRE in culture, effective against these bacteria in biofilms, and efficacious in a model system of eukaryotic infection. Structures and kinetics of these compounds will be presented and future directions discussed.

scholarly journals Adipocyte Biology from the Perspective of In Vivo Research: Review of Key Transcription Factors

2021 ◽  
Vol 23 (1) ◽  
pp. 322
Author(s):  
Maria N. Evseeva ◽  
Maria S. Balashova ◽  
Konstantin Y. Kulebyakin ◽  
Yury P. Rubtsov
Keyword(s):  
Adipose Tissue ◽  
Transcription Factors ◽  
Metabolic Disorders ◽  
Adipogenic Differentiation ◽  
In Vivo Studies ◽  
Research Review ◽  
Treatment And Prevention

Obesity and type 2 diabetes are both significant contributors to the contemporary pandemic of non-communicable diseases. Both disorders are interconnected and associated with the disruption of normal homeostasis in adipose tissue. Consequently, exploring adipose tissue differentiation and homeostasis is important for the treatment and prevention of metabolic disorders. The aim of this work is to review the consecutive steps in the postnatal development of adipocytes, with a special emphasis on in vivo studies. We gave particular attention to well-known transcription factors that had been thoroughly described in vitro, and showed that the in vivo research of adipogenic differentiation can lead to surprising findings.

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