Antimicrobial Agents
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2023 ◽  
Vol 83 ◽  
Author(s):  
S. K. Aldosary ◽  
S. N. A. El-Rahman ◽  
S. S. Al-Jameel ◽  
N. M. Alromihi

Abstract Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.


2022 ◽  
Vol 70 (1) ◽  
Author(s):  
Yasintha S. Lugira ◽  
Fransisca D. Kimaro ◽  
Mkhoi L. Mkhoi ◽  
Samuel G. Mafwenga ◽  
Angelina A. Joho ◽  
...  

Abstract Background Urinary tract infection (UTI) is the most common and life-threatening bacterial infection among neonates. This study aimed to determine the prevalence, aetiology, and susceptible antimicrobial agents among neonates with UTI. Methods This was a cross-sectional analytical hospital-based study that included 152 neonates with clinical sepsis who were admitted at Dodoma regional referral hospital from January to June 2020. Bacterial growth of 1 × 103 colony forming units/mL of a single uropathogen was used to define the presence of UTI. Statistical analysis was performed using SPSS version 23.0 and multivariate analysis was used to determine the predicting factors of UTI. P <0.05 was regarded statistically significant. Results The prevalence of UTI was 18.4% (28/152). Klebsiella pneumoniae 64.3% (18/28) and Enterobacter spp. 35.7% (10/28) were the bacterial agents isolated. The bacterial isolates were 90%, and 60% sensitive to ciprofloxacin and amikacin, respectively. Low Apgar score (AOR = 12.76, 95% CI = 4.17–39.06, p<0.001), prolonged labour (AOR = 5.36, 95% CI = 1.28–22.52, p = 0.022), positive urine nitrite test (AOR = 26.67, 95% CI = 7.75–91.70, p<0.001), and positive leucocyte esterase test (AOR = 6.64, 95% CI = 1.47–29.97, p = 0.014) were potential predictors of UTI. Conclusion The prevalence of UTI confirmed by urine culture among neonates that were included in the present study indicates that this problem is common in the population where the study was conducted. Klebsiella pneumoniae and Enterobacter spp. were the uropathogens which were isolated. Ciprofloxacin, nitrofurantoin, and amikacin were sensitive to the isolated uropathogens.


2022 ◽  
Vol 8 ◽  
Author(s):  
Entesar A. Hassan ◽  
Ihsan A. Shehadi ◽  
Awatef M. Elmaghraby ◽  
Hadir M. Mostafa ◽  
Salem E. Zayed ◽  
...  

In the present study, a general approach for the synthesis of 1-(1H-indol-3-yl)-3,3-dimercaptoprop-2-en-1-one (1) and 5-(1H-indol-3-yl)-3H-1,2-dithiole-3-thione (2) was performed. They are currently used as efficient precursors for the synthesis of some new compounds bearing five- and/or six-membered heterocyclic moieties, e.g., chromenol (3, 4), 3,4-dihydroquinoline (7, 8) and thiopyran (10, 12)-based indole core. In addition, molecular docking studies were achieved, which showed that all the newly synthesized compounds are interacting with the active site region of the target enzymes, the targets UDP-N-acetylmuramatel-alanine ligase (MurC), and human lanosterol14α-demethylase, through hydrogen bonds and pi-stacked interactions. Among these docked ligand molecules, the compound (9) was found to have the minimum binding energy (−11.5 and −8.5 Kcal/mol) as compared to the standard drug ampicillin (−8.0 and −8.1 Kcal/mol) against the target enzymes UDP-N-acetylmuramatel-alanine ligase (MurC), and Human lanosterol14α-demethylase, respectively. Subsequently, all new synthesized analogues were screened for their antibacterial activities against Gram-positive (Bacillus subtilis), and Gram-negative bacteria (Escherichia coli), as well as for antifungal activities against Candida albicans and Aspergillus flavus. The obtained data suggest that the compounds exhibited good to excellent activity against bacterial and fungi strains. The compound (E)-2-(6-(1H-indole-3-carbonyl)-5-thioxotetrahydrothieno [3,2-b]furan-2(3H)-ylidene)-3-(1H-indol-3-yl)-3-oxopropanedithioic acid (9) showed a high binding affinity as well as an excellent biological activity. Therefore, it could serve as the lead for further optimization and to arrive at potential antimicrobial agent.


2022 ◽  
Vol 10 (1) ◽  
pp. 185
Author(s):  
Davide Roncarati ◽  
Vincenzo Scarlato ◽  
Andrea Vannini

Since the discovery of penicillin in the first half of the last century, antibiotics have become the pillars of modern medicine for fighting bacterial infections. However, pathogens resistant to antibiotic treatment have increased in recent decades, and efforts to discover new antibiotics have decreased. As a result, it is becoming increasingly difficult to treat bacterial infections successfully, and we look forward to more significant efforts from both governments and the scientific community to research new antibacterial drugs. This perspective article highlights the high potential of bacterial transcriptional and posttranscriptional regulators as targets for developing new drugs. We highlight some recent advances in the search for new compounds that inhibit their biological activity and, as such, appear very promising for treating bacterial infections.


Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 104
Author(s):  
James V. Rogers ◽  
Veronica L. Hall ◽  
Charles C. McOsker

Antimicrobial resistance (AMR) is a concerning global threat that, if not addressed, could lead to increases in morbidity and mortality, coupled with societal and financial burdens. The emergence of AMR bacteria can be attributed, in part, to the decreased development of new antibiotics, increased misuse and overuse of existing antibiotics, and inadequate treatment options for biofilms formed during bacterial infections. Biofilms are complex microbiomes enshrouded in a self-produced extracellular polymeric substance (EPS) that is a primary defense mechanism of the resident microorganisms against antimicrobial agents and the host immune system. In addition to the physical protective EPS barrier, biofilm-resident bacteria exhibit tolerance mechanisms enabling persistence and the establishment of recurrent infections. As current antibiotics and therapeutics are becoming less effective in combating AMR, new innovative technologies are needed to address the growing AMR threat. This perspective article highlights such a product, CMTX-101, a humanized monoclonal antibody that targets a universal component of bacterial biofilms, leading to pathogen-agnostic rapid biofilm collapse and engaging three modes of action—the sensitization of bacteria to antibiotics, host immune enablement, and the suppression of site-specific tissue inflammation. CMTX-101 is a new tool used to enhance the effectiveness of existing, relatively inexpensive first-line antibiotics to fight infections while promoting antimicrobial stewardship.


Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 108
Author(s):  
Arya Nair ◽  
Rashmi Mallya ◽  
Vasanti Suvarna ◽  
Tabassum Asif Khan ◽  
Munira Momin ◽  
...  

Microbial pathogens are the most prevalent cause of chronic infections and fatalities around the world. Antimicrobial agents including antibiotics have been frequently utilized in the treatment of infections due to their exceptional outcomes. However, their widespread use has resulted in the emergence of multidrug-resistant strains of bacteria, fungi, viruses, and parasites. Furthermore, due to inherent resistance to antimicrobial drugs and the host defence system, the advent of new infectious diseases, chronic infections, and the occurrence of biofilms pose a tougher challenge to the current treatment line. Essential oils (EOs) and their biologically and structurally diverse constituents provide a distinctive, inexhaustible, and novel source of antibacterial, antiviral, antifungal, and antiparasitic agents. However, due to their volatile nature, chemical susceptibility, and poor solubility, their development as antimicrobials is limited. Nanoparticles composed of biodegradable polymeric and inorganic materials have been studied extensively to overcome these limitations. Nanoparticles are being investigated as nanocarriers for antimicrobial delivery, antimicrobial coatings for food products, implantable devices, and medicinal materials in dressings and packaging materials due to their intrinsic capacity to overcome microbial resistance. Essential oil-loaded nanoparticles may offer the potential benefits of synergism in antimicrobial activity, high loading capacity, increased solubility, decreased volatility, chemical stability, and enhancement of the bioavailability and shelf life of EOs and their constituents. This review focuses on the potentiation of the antimicrobial activity of essential oils and their constituents in nanoparticulate delivery systems for a wide range of applications, such as food preservation, packaging, and alternative treatments for infectious diseases.


Biomolecules ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 131
Author(s):  
Thibaut Barbier ◽  
Alexia Barbry ◽  
Jérémy Magand ◽  
Cédric Badiou ◽  
Floriane Davy ◽  
...  

The benzo[b]thiophene nucleus and the acylhydrazone functional group were combined to prepare three new series of compounds for screening against Staphylococcus aureus. The reaction of substituted benzo[b]thiophene-2-carboxylic hydrazide and various aromatic or heteroaromatic aldehydes led to a collection of 26 final products with extensive structural diversification on the aromatic ring and on position 6 of the benzo[b]thiophene nucleus. The screening lead to the identification of eight hits, including (E)-6-chloro-N’-(pyridin-2-ylmethylene)benzo[b]thiophene-2-carbohydrazide (II.b), a non-cytotoxic derivative showing a minimal inhibitory concentration of 4 µg/mL on three S. aureus strains, among which were a reference classical strain and two clinically isolated strains resistant to methicillin and daptomycin, respectively.


Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 97
Author(s):  
Md Bashir Uddin ◽  
Mohammad Nurul Alam ◽  
Mahmudul Hasan ◽  
S. M. Bayejed Hossain ◽  
Mita Debnath ◽  
...  

Zoonotic and antimicrobial-resistant Escherichia coli (hereafter, E. coli) is a global public health threat which can lead to detrimental effects on human health. Here, we aim to investigate the antimicrobial resistance and the presence of mcr-1 gene in E. coli isolated from chicken feces. Ninety-four E. coli isolates were obtained from samples collected from different locations in Bangladesh, and the isolates were identified using conventional microbiological tests. Phenotypic disk diffusion tests using 20 antimicrobial agents were performed according to CLSI-EUCAST guidelines, and minimum inhibitory concentrations (MICs) were determined for a subset of samples. E. coli isolates showed high resistance to colistin (88.30%), ciprofloxacin (77.66%), trimethoprim/sulfamethoxazole (76.60%), tigecycline (75.53%), and enrofloxacin (71.28%). Additionally, the pathotype eaeA gene was confirmed in ten randomly selected E. coli isolates using primer-specific polymerase chain reaction (PCR). The presence of mcr-1 gene was confirmed using PCR and sequencing analysis in six out of ten E. coli isolates. Furthermore, sequencing and phylogenetic analyses revealed a similarity between the catalytic domain of Neisseria meningitidis lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, indicating that the six tested isolates were colistin resistant. Finally, the findings of the present study showed that E. coli isolated from chicken harbored mcr-1 gene, and multidrug and colistin resistance. These findings accentuate the need to implement strict measures to limit the imprudent use of antibiotics, particularly colistin, in agriculture and poultry farms.


2022 ◽  
Vol 51 (4) ◽  
pp. 795-804
Author(s):  
Mariya Zenkova ◽  
Ludmila Melnikova

Introduction. Sprouted grain can cause food poisoning, since inappropriate conditions can promote the growth of pathogenic microorganisms on the grain surface. As a result, products of long-term storage use thermally-treated sprouted grain, the parameters of which depend on the initial bacteria content. There are different ways to reduce bacterial contamination of sprouted grain, each of which has its own advantages and disadvantages. Natural substances with antimicrobial properties, such as medicinal herbs, can serve as decontaminators. However, no scientific research has been performed so far to determine the exact temperature of grain sprouting to minimize its microbiological contamination. The research objective was to investigate the effect of antimicrobial agents and sprouting conditions on the microflora of wheat and buckwheat grain. Study objects and methods. The study featured wheat grain and green buckwheat grain. A set of experiments was performed to define the effect of antimicrobial agents and sprouting conditions on the quantity of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), molds, and yeasts. During sprouting at 10–30°C for 90 h, the grain was irrigated with distilled water, potassium permanganate solution (KMnO4), calendula infusion, and celandine i nfusion. QMAFAnM and the count of molds and yeasts were determined by standard methods; the qualitative analysis of the microflora was based on their morphological and cultural characteristics. Results and discussion. Microflora development during sprouting of wheat and buckwheat grains was controlled by selecting appropriate conditions and grain treatment methods. The herbal infusions for sprouting reduced the total microbial insemination of grain during sprouting by 52–68%; the calendula infusion reduced the contamination with molds by 47–51%, yeasts – by 100%. Conclusion. The research revealed the total microbial count and the count of mold and yeast colonies in dry sprouted grain. The optimal temperature of sprouting wheat and buckwheat was 20 ± 2°C in the infusion of medicinal herbs: it minimized the microflora of sprouted grain and reduced the sprouting time to 46 h. Calendula infusion could be recommended for commercial use in order reduce the microbiological contamination of sprouted grain. The initial microbial population of the product was found to affect the mode of heat treatment in long-term storage products.


Author(s):  
Zehong Cao ◽  
Guangjie Cheng

Over the past 2 decades, more than 20 new infectious diseases have emerged. Unfortunately, novel antimicrobial therapeutics are discovered at much lower rates.


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