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PURPOSE: The purpose of this study was to assess the association between antifungal susceptibility as measured by minimum inhibitory concentration (MIC) and clinical outcomes in fungal keratitis. METHODS: This pre-specified secondary analysis of the Mycotic Ulcer Treatment Trial II (MUTT II) involved patients with filamentous fungal keratitis presenting to Aravind Eye Hospitals in South India. Antifungal susceptibility testing for natamycin and voriconazole was performed on all samples with positive fungal culture results according to Clinical and Laboratory Standards Institute Guidelines. The relationship between MIC and clinical outcomes of best-corrected visual acuity, infiltrate or scar size, corneal perforation, need for therapeutic penetrating keratoplasty, and time to re-epithelialization were assessed. RESULTS: We obtained MIC values from 141 patients with fungal keratitis. The most commonly cultured organisms were Aspergillus (46.81%, n = 66) and Fusarium (44.68%, n = 63) species. Overall, there was no association between antifungal MICs and clinical outcomes. Subgroup analysis revealed that among Fusarium-positive cases, higher voriconazole MIC was correlated with worse three-month best-corrected visual acuity (p = 0.03), increased need for therapeutic penetrating keratoplasty (p = 0.04), and time to re-epithelialization (p = 0.03). No significant correlations were found among Aspergillus-positive cases. There were no significant correlations found between natamycin MIC and clinical outcomes among organism subgroups. CONCLUSIONS: Decreased susceptibility to voriconazole was associated with increased odds of requiring a therapeutic penetrating keratoplasty in Fusarium-positive cases. Susceptibility to natamycin was not associated with any of the measured outcomes.

Heavy metal ions produced by industrialization are the major source of pollution that affect both humans and other animals in different ways. In the current study, lead-resistant gram-negative Klebsiella pneumoniae strain PbS3A2 was isolated from industrial effluent around the Chokera, in Faisalabad, Pakistan. The minimum inhibitory concentration revealed that K. pneumoniae PbS3A2 can resist Pb up to 20 mM and other toxic heavy metal ions including 3 mM (Zn2+), 2 mM (Ni2+), 4 mM (Cu2+), 6 mM (Cd2+), 8 mM (As3+), with the resistance order as (Pb > As > Cd > Cu > Zn > Ni). Lead stress triggered a significant rise in the production of antioxidant enzymes including Superoxide dismutase (247%) Glutathione S-transferase (50%), and ascorbate peroxidase (17%) as well as a considerable decrease was observed in peroxidase (46%), and catalase (5%). Metal ions can be trapped by functional groups such as phosphate, carboxyl, and amide groups that are fully engaged in Pb adsorption were shown by FTIR as well as intracellular accumulation confirmed by scanning electron microscopy and energy dispersive X-ray. From the obtained results, K. pneumoniae may be a potential candidate for lead bioremediation of industrial effluent. [ABSTRACT FROM AUTHOR]

Research on Actinomycetota species is becoming increasingly significant, not only for their ecological and taxonomic aspects, but primarily for their unique metabolites that hold potential for therapeutic uses. In this study, Actinomycetota bacteria strains were isolated from the sediments of two seagrass meadows, Thalassia hemprichii and Syringodium isoetifolium, as well as from plain sediment (without seagrasses) at Mjimwema, Tanzania, in the Western Indian Ocean. The isolates were identified through their morphological and biochemical characteristics, along with molecular techniques. Additionally, antimicrobial and cytotoxicity tests were also conducted. Fifteen different strains of Actinomycetota were isolated, and based on phenotypic and phylogenetic characteristics, they were grouped into seven different genera, namely: Micrococcus, Microbacterium, Ornithinimicrobium, Cellulomonas, Cellulosimicrobium, Luteimicrobium, and Dietzia. Results of 16S rRNA gene sequence analysis showed eight potential new species of Actinomycetota from these sediments. Genus Micrococcus was dominant in all samples, followed by Microbacterium. Furthermore, genera Ornithinimicrobium and Cellulosimicrobium appeared only in T. hemprichii sediment, while Luteimicrobium and Cellulomonas were observed in plain sediment only. To the best of our knowledge, genera Cellulomonas and Luteimicrobium are reported for the first time in marine sediment. The crude extract of the isolates exhibited antimicrobial effects against Candida albicans, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. The results revealed that sediments within seagrass meadows harbor unique Actinomycetota species capable of producing secondary metabolites with potential therapeutic uses. Therefore, additional research is necessary to thoroughly characterize the novel species and identify the chemical compounds responsible for the observed antimicrobial activity and bioprospecting. [ABSTRACT FROM AUTHOR]

A 42‐year‐old Vietnamese egg factory worker in Ishikawa prefecture, Japan, presented with itchy concentric erythema on the trunk and left calf. The lesions tested positive by direct potassium hydroxide examination, and two fungal strains were isolated. The isolates produced conidia abundantly and were morphologically indistinguishable from Trichophyton mentagrophytes/interdigitale, but were identified as Trichophyton indotineae by internal transcribed spacer sequence of ribosomal DNA. The lesions were refractory to treatment with topical luliconazole (LLCZ) cream for 4 weeks but subsided with oral itraconazole (ITCZ) 100 mg/day for 4 weeks in combination with topical lanoconazole (LCZ) cream. The lesions recurred 6 weeks after discontinuation of oral ITCZ, and an additional isolate was cultured. The minimum inhibitory concentrations of antimycotics for the isolate cultured at the first visit were: terbinafine (TBF) 0.03 μg/mL, ITCZ 0.015 μg/mL, LLCZ 0.0005 μg/mL, and LCZ 0.002 μg/mL. No TBF‐resistant mutation in the amino acid sequence of squalene epoxidase, i.e., Leu 393 Ser/Phe or Phe 397 Leu, was detected in the isolate. The reason for recalcitrance in this case, despite the isolate's sensitivity to antimycotics, was unclear. Possible factors include insufficient use of the antimycotics, incomplete removal of abundantly produced conidia from the lesions, the patient's environment, and a language gap between the patient and physician hindering communication. [ABSTRACT FROM AUTHOR]

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant public health problem. This study investigated the antimicrobial properties and mechanisms of berberine (BBR), a plant alkaloid, against MRSA, evaluating its potential to enhance antibiotic therapy. Results: Berberine only demonstrated variable but significant inhibitory effects on 50 clinical MRSA strains. When combined with antibiotics, synergistic effects were observed only with amikacin in 6 of the 50 MRSA strains. BBR disrupted MRSA cell wall integrity, leading to leakage of cellular contents. Network pharmacology analysis revealed that BBR targets multiple pathways essential for bacterial survival. Conclusion: The study confirmed the potent antimicrobial activity of berberine against MRSA and its capability to act synergistically with traditional antibiotics. Berberine's impact on cell wall integrity and bacterial survival pathways highlights its potential as an adjunct therapy in MRSA treatment. [ABSTRACT FROM AUTHOR]

Pests and diseases have caused significant problems since the domestication of crops, resulting in economic loss and hunger. To overcome these problems, synthetic pesticides were developed to control pests; however, there are significant detrimental side effects of synthetic pesticides on the environment and human health. There is an urgent need to develop safer and more sustainable pesticides. Industrial hemp is a reservoir of compounds that could potentially replace some synthetic bactericides, fungicides, and insecticides. We determined the efficacy of industrial hemp extracts against Pseudomonas syringae pv. tabaci (PSTA), Pseudomonas syringae pv. tomato (PSTO), and Erwinia carotovora (EC). The study revealed a minimum inhibitory concentration (MIC) of 2.05 mg/mL and a non-inhibitory concentration (NIC) of 1.2 mg/mL for PSTA, an MIC of 5.7 mg/mL and NIC of 0.66 mg/mL for PSTO, and an MIC of 12.04 mg/mL and NIC of 5.4 mg/mL for EC. Time-kill assays indicated the regrowth of E. carotovora at 4 × MIC after 15 h and P. syringae pv. tomato at 2 × MIC after 20 h; however, P. syringae pv. tabaci had no regrowth. The susceptibility of test bacteria to hemp extract can be ordered from the most susceptible to the least susceptible, as follows: P. syringae pv. tabaci > P. syringae pv. tomato > E. carotovora. Overall, the data indicate hemp extract is a potential source of sustainable and safe biopesticides against these major plant pathogens. [ABSTRACT FROM AUTHOR]

The fungal pathogen Batrachochytrium dendrobatidis (Bd), causing chytridiomycosis, continues to threaten the existence of hundreds of amphibian species worldwide. It has remained difficult to predict the sensitivity of species to the disease, but skin-secreted antimicrobial peptides have been proposed to provide effective defences. In this study we tested this hypothesis by assessing in vitro the bioactivity of the antimicrobial peptide Brevinin-1Da, which is known to be synthesized in the skin of agile frogs (Rana dalmatina), against two isolates (IA042 and Hung_2014) of the highly virulent Global Pandemic Lineage (GPL) of Bd. Our results showed for the first time that Brevinin-1Da can inhibit the growth of Bd, and its efficacy appeared to be similar to that of other members of the Brevinin-1 peptide family isolated from other Ranid frogs. Finally, efficacy of Brevinin-1Da appeared to be higher against the Bd isolate Hung_2014, which was isolated in the core area of Rana dalmatina’s geographic distribution, and lower against IA042, which was isolated from outside the current distribution of this frog species. These results show that the efficacy of Brevinin-1Da may contribute to the previously documented resistance of agile frogs and that the sensitivity of Bd to the chemical defence of hosts can vary depending on the isolate. [ABSTRACT FROM AUTHOR]

Background: The global spread of antimicrobial resistance (AMR) represents one of the most significant challenges of our generation. It is crucial to continuously monitor AMR, not only by investigating clinical, pathogenic strains but also by monitoring commensal bacterial strains, as they can serve as natural reservoirs of resistance. Infections caused by Enterococcus species are increasingly recognized as emerging threats to both animal and public health. Among economically important livestock, poultry as a major source of animal protein for humans is a frequent carrier of enterococci, and also of sporadically detected clinical disease. Methods: This study aimed to determine the antimicrobial susceptibility profile of Enterococcus strains (n = 499) isolated from chicken farms in Hungary. The minimum inhibitory concentration (MIC) was determined for 15 antibiotics, including 10 with established clinical breakpoints. Results: The strains exhibited good sensitivity to amoxicillin, one of the first-line treatments for Enterococcus infections in veterinary medicine, with only 20.8% showing resistance. However, we observed an alarming 27.9% resistance rate to vancomycin, which is reserved to treat infections caused by multidrug-resistant strains in humans. A comparison of our findings with Hungarian hospital records revealed that the resistance patterns of poultry-derived Enterococcus faecalis strains were very similar to those of human isolates, particularly regarding penicillins and aminoglycosides. Conclusions: Overall, the increasing rates of AMR reinforce the importance of conducting periodic studies to establish long-term trends. For multidrug-resistant strains, next-generation sequencing is recommended to elucidate the genetic basis of resistance. [ABSTRACT FROM AUTHOR]

Background: Widespread use of antibiotics has led to a global increase in resistance. The Escherichia coli bacterium is a facultative pathogen that often develops antibiotic resistance and is easily transmitted, not only in animal health but also in public health. Within the poultry sector, domestic fowl is widespread and one of the most dynamically growing sectors, which is why regular, extensive monitoring is crucial. Among economically important livestock, poultry as a major source of animal protein for humans is a frequent carrier of Escherichia coli, also with sporadically detected clinical disease. Methods: Our research evaluates the susceptibility of commensal Escherichia coli strains, isolated from large domestic fowl flocks in Hungary, to antibiotics of animal and public health importance, by determining the minimum inhibitory concentration value. Results: A total of 410 isolates were tested, with the highest level of resistance being found for florfenicol (62.7%). Particularly alarming are the resistance rates to enrofloxacin (52.9%), colistin (30.7%), and ceftriaxone (23.9%). We also found a resistance of 56.1% to amoxicillin and 22.2% to amoxicillin-clavulanic acid, which suggests that the majority of strains are β-lactamase-producing. When compared with the national human resistance data, we found with similar values for amoxicillin and amoxicillin-clavulanic acid, but the resistance rates of aminoglycosides, fluoroquinolones, and potency sulfonamide were worse in animal health. Conclusions: In conclusion, our results suggest that periodic surveys should be carried out and that long-term trends can be established that allow the monitoring of resistance patterns over time. For multidrug-resistant strains, new generation sequencing can be used to investigate the genetic background of resistance. [ABSTRACT FROM AUTHOR]

The global spread of antimicrobial resistance is one of the most significant challenges of the 21st century. The waterfowl sector is an economically decisive part of the poultry industry, yet it remains under-researched, and its antibiotic usage is less monitored. Our study aimed to determine the antimicrobial susceptibility of avian pathogenic Salmonella strains, which are still prevalent in ducks and geese, against antibiotics critical for both animal and human health, and to compare these findings with human resistance data. We analyzed 71 Salmonella strains, collected by the National Reference Laboratory from samples originating from 29 settlements across Hungary between 2022 and 2023, using the minimum inhibitory concentration (MIC) method. Notably, the duck strains (n = 52) exhibited 57.7% resistance to potentiated sulfonamides, 28.8% resistance to doxycycline, and 25% resistance to cefotaxime. Among the geese strains (n = 19), 52.6% showed resistance to potentiated sulfonamides, followed by 26.3% resistance to doxycycline and amoxicillin–clavulanic acid, and 15.8% resistance to cefotaxime, ceftiofur, and ceftriaxone. When compared to human resistance data, we found significantly lower resistance levels for amoxicillin in ducks (20.0%) and geese (8.3%) in the Dél-Alföld region, compared to ampicillin resistance in human samples (45.4%), in which amoxicillin analog is an antibiotic in human medicine. Resistance to ciprofloxacin was only observed in ducks (2.0%), whereas pefloxacin resistance in human medicine was notably higher (22.3%). Overall, the results for the waterfowl sector in the Dél-Alföld region of Hungary align with the international literature in several aspects. Further investigation using next-generation sequencing to identify the genetic basis of multi-resistant strains is warranted. [ABSTRACT FROM AUTHOR]

Essential oils (EOs) from plants have attracted the attention of scientists due to their multiple biological activities. Antimicrobial activity of essential oils is the main reason for their widespread use in industries, which is determined through minimum inhibitory concentration (MIC) by using in vitro models. Therefore, the MIC is a crucial parameter to evaluate the antimicrobial potential of EOs. 492 papers were screened through the critical review of the related literatures in the past 50 years using four databases and read deeply for an outline. This review first listed common MIC determination methods of EOs, including agar diffusion method, agar dilution method, broth dilution method, E-Test, thin-layer chromatography-bioautography, etc. and their merits and demerits were introduced in detail. Agar and broth dilution methods are the gold standards in a more exact approach for MIC determination. Then, their functions and factors influencing the accuracy were listed and analyzed deeply. The application of the MIC determination in food and pharmaceuticals was finally discussed. This study is believed to help researchers to choose the right method and conditions for research and development of the tested EOs. [ABSTRACT FROM AUTHOR]

Agricultural water is commonly treated with chlorine-based disinfectants, which are impacted by water quality. Understanding how water quality influences disinfectants such as chlorine dioxide (ClO2) against pathogenic bacteria is important for creating efficacious sanitation regimens. In this study, the minimum inhibitory concentration (MIC) of ClO2 needed to achieve a 3-Log reduction against Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes was compared across agricultural water samples. Sterile ddH2O served as a control to compare with environmental samples from Salinas Valley, CA, and laboratory standards. To test different dosages and water qualities, stock ClO2 was diluted in 24-well plates with target concentrations of 10, 5, 2.5, and 1.25 mg/L. Well plates were inoculated with pathogens and treated with sanitizer for 5 min. Following treatment, surviving pathogens were enumerated using viable cell counts. The results demonstrate that groundwater samples had the highest water quality of the environmental samples and required the lowest concentration of disinfectant to achieve 3-Log reduction against both bacteria, with MIC between 1.4 and 2.0 mg/L. Open-source samples had lower water quality and required a higher concentration of ClO2 for 3-Log reduction, with MIC between 2.8 and 5.8 mg/L for both pathogens. There was no correlation between pH, turbidity, or conductivity/TDS and reduction for either STEC or L. monocytogenes , suggesting no individual water metric was driving reduction. A lower dosage was required to achieve 3-Log reduction against STEC, while L. monocytogenes required greater concentrations to achieve the same level of reduction. Overall, these results help guide growers in using ClO2 as a broad-spectrum disinfectant and demonstrate its efficacy in reaching 3-Log reduction across agricultural water samples. [ABSTRACT FROM AUTHOR]

(Z)-1-(4-chlorophenyl)-3-(3-((E)-3-(4-chlorophenyl)-3-oxoprop-1-en-1-yl)phenyl)prop-2-en-1-one (CCOP) has been explored through both experimental and theoretical investigation. The density functional theory was used to perform the theoretical computations. The compound's geometrical structure was optimized, and comparisons were made between experimental results and calculated vibrational wavenumbers. Raman scattering active regions and infrared intensities have been determined. The Light Harvesting Efficiency of CCOP was determined to be 0.88, derived from an f value of 0.9735, indicating that 88% of incident light can be converted into influence. The f values for various solvents were found to be 0.9119 (ethanol), 0.9024 (DMSO), 0.8919 (water), and 0.8802 (gas). Wave function analysis identifies electron depletion areas using the electron localization function. Through the study of molecular electrostatic potential and Fukui functions, the nucleophilic sites are discovered. Research on donor-acceptor interactions examines the compound's hyperconjugate interactions and intra- and intermolecular charge transfer. The antibacterial and antifungal activity assay revealed that CCOP has moderate antibacterial and antifungal properties. The minimum inhibitory concentration (MIC) values for Staphylococcus sp. and Pseudomonas sp. were found to be 750 µg/mL, while Escherichia coli and Salmonella sp. showed MIC values of 500 µg/mL. The substance's drug-like qualities were demonstrated using Lipinski's criteria of five, and the molecule is advised for usage in pharmaceuticals utilizing ADMET form. Docking of COOP with bacterial and fungal proteins have been done, and lowest binding energy −7.96 and −6.96 kcal/mol has been attained for 3X0V and 3CHY protein. Exploiting molecular dynamics simulations, stability of COOP compound has been investigated. [ABSTRACT FROM AUTHOR]

Melatonin (MLT) is a methoxyindole that has potent antioxidant actions, anti-inflammatory, and antiapoptotic capacity. However, its in vitro antibacterial capacity has been the least studied of its properties. Dimethylsulfoxide (DMSO) has been the most used solvent for these tests, but it shows an antimicrobial effect if it is not dissolved. Cyrene™ is a new solvent that has emerged as an alternative to DMSO. Therefore, this study aimed to determine the antimicrobial capacity of MLT by MIC assays, using Cyrene™ as a solvent. Likewise, the solubility of MLT in this solvent and whether it exerted any effect on bacterial growth at different percentages was also determined. Different dilutions of MLT in Cyrene™ with different concentrations, were prepared. No growth inhibition caused by MLT was observed. The growth inhibition observed was because of Cyrene™. The maximum amount of MLT that can be diluted in 100% Cyrene is 10 mg/mL, but this percentage of solvent shows a bactericidal effect. Therefore, it must be dissolved at 5% to avoid this effect, so only 4 mg/mL of MLT can be diluted in it. Therefore, if no other solvents are available, the in vitro antibacterial role of MLT cannot be adequately assessed. [ABSTRACT FROM AUTHOR]

Lichens are symbiotic organisms with unique secondary metabolism. Various metabolites from lichens have shown antimicrobial activity. Nevertheless, very few studies have investigated the antimicrobial potential of the volatile compounds they produce. This study investigates the chemical composition and antimicrobial properties of volatile compounds from Pseudevernia furfuracea collected in two regions of Morocco. Hydrodistillation was used to obtain volatile compounds from samples collected in the High Atlas and Middle Atlas. Gas chromatography–mass spectrometry (GC-MS) analysis identified phenolic cyclic compounds as the primary constituents, with atraric acid and chloroatranol being the most abundant. Additionally, eight compounds were detected in lichens for the first time. The antimicrobial activity of these compounds was assessed using disc diffusion and broth microdilution methods. Both samples demonstrated significant antimicrobial effects against multidrug-resistant human bacteria, reference microorganisms, fish pathogens, and Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 1000 µg/mL to 31.25 µg/mL. This study provides the first report on the volatile compounds from Pseudevernia furfuracea and their antimicrobial effects, particularly against fish pathogens, suggesting their potential as novel antimicrobial agents for human and veterinary use. Further research is warranted to explore these findings in more detail. [ABSTRACT FROM AUTHOR]

Eggerthella lenta (E. lenta) is known to cause intra-abdominal and anaerobic bloodstream infections. However, clinical insights and information on antimicrobial susceptibility in E. lenta infections are limited. This study aimed to elucidate the clinical characteristics and antimicrobial susceptibility of E. lenta infections. Patients with E. lenta isolated from various specimens who presented at Aichi Medical University Hospital between January 2018 and December 2022 were included. Patient information was retrospectively collected from electronic medical records. Logistic regression analysis was conducted to identify risk factors for bloodstream infections. The antimicrobial susceptibility of various antimicrobial agents against isolated strains was investigated. During the study period, seventy cases were classified as infection cases. The median age of patients was 69 years (range: 15-100 years), and 48 (68.6%) were males. The most common site of infection was the lower digestive tract (54.3%). In 70.4% of cases, polymicrobial infections occurred. Community-acquired infection was a significant risk factor for bloodstream infection, with an odds ratio of 4.94 (95% confidence interval: 1.02-23.9). The 30-day mortality rate was 10.0%. Univariate analysis showed lower mortality in patients who underwent surgical intervention than in those who did not (42.9% vs 57.1%, p = 0.02). The proportion of minimal inhibitory concentrations (MICs) of = 32 µg/mL for piperacillin-tazobactam was 6.3%. Additionally, the proportions of MICs of = 8 µg/mL for imipenem and meropenem were 1.4% and 0%, respectively. E. lenta should be considered when blood cultures yield gram-positive rods in community-acquired intra-abdominal infections. Effective treatment involves both antimicrobial agents and surgical interventions. [ABSTRACT FROM AUTHOR]

We compared the minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of azoles in antifungal drug‐susceptible, terbinafine‐resistant, and lowly itraconazole (ITCZ)‐susceptible strains of dermatophytes. To assess the MICs of ITCZ, ravuconazole (RVCZ), efinaconazole (EFCZ), and luliconazole (LUCZ) in the isolates, broth microdilution assays were performed based on the Clinical and Laboratory Standards Institute M38‐A2 guidelines with modifications. After the assays for determining the MICs, the inoculum suspensions in wells were resuspended, then 10 μL of the growth solution in each well was inoculated onto potato dextrose agar with the use of a pipette. After 7 days of incubation at 28°C, the MFCs were determined as the lowest concentration of a drug that allowed the growth of colonies on the potato dextrose agar. The MICs in the dermatophytes were <0.03 to >32 mg/L for ITCZ, <0.03 to 4 mg/L for RVCZ, <0.03 to 2 mg/L for EFCZ, and <0.03 mg/L for LUCZ. The MFCs in the dermatophytes were 1 to >32 mg/L for ITCZ, 0.06 to >32 mg/L for RVCZ, <0.03 to 4 mg/L for EFCZ, and <0.03 to 2 mg/L for LUCZ. If the drug susceptibility test shows that the fungi are resistant to the drug, the treatment can be changed to a susceptible drug in advance, or if the fungi are low‐susceptible, the treatment can be done with the recognition that it may require a longer treatment period than usual. [ABSTRACT FROM AUTHOR]

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) is a significant public health problem. This study investigated the antimicrobial properties and mechanisms of berberine (BBR), a plant alkaloid, against MRSA, evaluating its potential to enhance antibiotic therapy. Results Berberine only demonstrated variable but significant inhibitory effects on 50 clinical MRSA strains. When combined with antibiotics, synergistic effects were observed only with amikacin in 6 of the 50 MRSA strains. BBR disrupted MRSA cell wall integrity, leading to leakage of cellular contents. Network pharmacology analysis revealed that BBR targets multiple pathways essential for bacterial survival. Conclusion The study confirmed the potent antimicrobial activity of berberine against MRSA and its capability to act synergistically with traditional antibiotics. Berberine’s impact on cell wall integrity and bacterial survival pathways highlights its potential as an adjunct therapy in MRSA treatment.

Although chemical antifungal preservatives are often used in various food products, the use of these substances has been limited due to their harmful effects on human health and the environment. Researchers have recently sought to replace these chemical compounds with natural and less dangerous substances. In this regard, using essential oils of medicinal plants can be considered a suitable alternative due to fewer side effects. Therefore, in the present research, after preparing the Badrashboo plant from the fields of Golmarz village located near Urmia city and drying it, extracting the essential oil from the Badrashboo was carried out using a Clevenger, and the antifungal effect of Badrashboo essential oil on some important fungal strains with disc diffusion agar and well diffusion agar, minimum inhibitory concentration, minimum fungicidal concentration and the interaction of Badrashboo essential oil with Nystatin were performed. The results of disk diffusion agar and well diffusion agar tests showed that Badrashboo essential oil had a significant antifungal effect on all studied fungal strains. The results of the minimum inhibitory concentration of essential oil for strains of Saccharomyces cerevisiae, Candida albicans, Aspergillus niger, Fusarium solani, and Penicillium expansum were 8, 16, 2, 8, and 4 mg/mL, respectively. The minimum fungicidal concentration for the mentioned strains was 32, 64, 8, 16, and 32 mg/mL respectively. Also, the results of the interaction of Badrashboo essential oil with Nystatin indicated the synergistic effect of Badrashboo essential oil with Nystatin. Considering the significant antifungal effect observed for Badrashboo essential oil in the present study, it can be used in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is a serious challenge for medicine and society as a whole. Among the bacteria that pose the greatest threat to human health due to their growing antibiotic resistance are Escherichia coli, Staphylococcus aureus and Salmonella spp. The main reasons behind this problem are the misuse of antibiotics and lack of new antimicrobials, which are difficult to develop due to the complexity of the mechanisms of microbial infections and their limited weak points. Moreover, the process of developing new drugs requires significant time and financial resources. The purpose of this article was to analyse the antibacterial properties of three tellurium derivatives against infections caused by E. coli, S. aureus and Salmonella spp. Materials and methods. During the experiment, we studied the antimicrobial activity against the abovementioned bacteria of the following organotellurium compounds of original synthesis that have not been previously described in literature: dioxyrocyclo-[4-methylphenyl] tellurochloride, 3-chloromethyl-dioxisinrocyclophenyl tellurochloride, and ethyltellurobenzal-[2-methoxy-3,5-dichloro] aniline. As a criterion for the microorganism’s sensitivity to organotellurium compounds, inhibition zone diameter was used. The paper applied the serial dilution method and the disk diffusion method. Results. The study of the three heterocyclic tellurium derivatives in various concentrations revealed a significant antibacterial effect of dioxyrocyclo-[4-methylphenyl] tellurochloride, whose minimum suppressive and minimum inhibitory concentrations against the bacteria in question we were able to determine. Minimum inhibitory concentrations for E. coli and S. aureus were 18.60 and 1.35 µg/ml, respectively. Disk diffusion showed that the inhibition zones range between 3 and 6 mm. E. coli and S. aureus strains were particularly sensitive to this compound. Ethyltellurobenzal-[2-methoxy-3,5-dichloro] aniline failed to produce a positive effect against E. coli, S. aureus and Salmonella spp. at any regimen, while 3-chloromethyl-dioxisinrocyclophenyl tellurochloride demonstrated moderate antimicrobial activity at a relatively low bacterial load.

Abstract The Clinical and Laboratory Standards Institute (CLSI) M27 guidelines are the recommended and most commonly used protocols for broth microdilution antifungal susceptibility testing of yeasts. However, these guidelines are limited to the use of 96-well assay plates, limiting assay capacity. With the increased risk of fungal resistance emerging in the community, it is important to have alternative protocols available, that offer higher throughput and can screen more than eight to ten potential antifungal compounds per plate. This study presents an optimised broth microdilution minimum inhibitory concentration (MIC) method for testing the susceptibility of yeasts in an efficient high throughput screening setup, with minimal growth variability and maximum reproducibility. We extend the M27 guidelines and optimise the conditions for 384-well plates. Validation of the assay was performed with ten clinically used antifungals (fluconazole, amphotericin B, 5-fluorocytosine, posaconazole, voriconazole, ketoconazole, itraconazole, caspofungin diacetate, anidulafungin and micafungin) against Candida albicans and Cryptococcus neoformans.

Abstract Minimum inhibitory concentration (MIC) denotes the in vitro benchmark indicating the quantity of antibiotic required to inhibit proliferation of specific bacterial strains. Determining MIC values corresponding to the infecting bacterial strain is paramount for tailoring appropriate antibiotic therapy. In the interim between specimen collection and laboratory-derived MIC outcomes, clinicians frequently resort to empirical therapy informed by retrospective analyses. Here introduces two deep learning approaches, a Convolutional Neural Network (CNN)-based model and an Enformer-based model, integrating genomic data of Klebsiella Pneumoniae and molecular structural data of 20 antibiotics to anticipate the MIC value of the bacterium for each antibiotic under consideration. These models demonstrate enhanced raw accuracy over the existing state-of-the-art model, which rely exclusively on genomic data. The CNN-based model achieves a notable 20% increase in raw accuracy while further mirroring the 1-tier accuracy of the state-of-the-art model. Although the Enformer-based model does not quite reach the performance levels of the CNN-based model, it offers an advantage by eliminating the need for arbitrary data processing steps. This streamlining of the data processing pipeline facilitates fast updates and improves the model interpretability. It is expected that these deep learning paradigms can significantly inform and bolster clinician decision-making during the empirical treatment phase.

Objective: The crucial aim of irrigation solutions used in root canal treatments is the elimination of biofilm which is considered an important virulence factor of Enterococcusfaecalis. Essential oils have been investigated to understand their efficacy for biofilm elimination in recent years. This study aimed to evaluate the antimicrobial and antibiofilm effects of Thymus vulgaris essential oils (TEO) and Origanum onites essential oils (OEO) on E. faecalis. Methods: The antimicrobial effectiveness of TEO and OEO against E. faecalis (ATCC 29212) was investigated by broth microdilution method, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The effect of TEO and OEO on preventing biofilm formation was evaluated by measuring biofilm biomass using crystal-violet method, and its effect on biofilm viability was evaluated by determining the number of living cells in the biofilm as colony-forming units. Biofilm viability was analyzed with one-sample t-test with statistical significance accepted as p

Abstract A recent scientific investigation has shown promising results of selenium nanoparticles (SeNPs) for the anticancer and antimicrobial activities. This study aims to evaluate the effects of PVP SeNPs on bacterial strains, including Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus), Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa). Also, its antitumor activity against the MRC-5 carcinoma cell line. SeNPs were prepared via gamma irradiation using PVP as a capping agent, and their size and morphological structure were determined using HRTEM. The size of the SeNPs ranged from 36 to 66.59 nm. UV–vis spectra confirmed the formation of SeNPs, while FTIR measurement confirmed a change in the PVP structure after adding selenium nanoparticles. The highest effect was reported on HepG2 by an IC50 with a value of 8.87 µg/ml, followed by HeLa, PC3, MCF-7, and Caco2 cell lines, respectively. Furthermore, ZOI reached 36.33 ± 3.05 mm. The best value of the minimum inhibitory concentration (MIC) was 0.313 µg/ml. Scanning electron microscope (SEM) imaging against bacteria showed deformations and distortions in their structures. Transmission electron (TEM) revealed ultrastructure changes in treated bacteria because of the free radicals that made cytotoxicity which confirmed by Electron spin resonance (ESR).

Abstract Purpose The purpose of this study was to assess the association between antifungal susceptibility as measured by minimum inhibitory concentration (MIC) and clinical outcomes in fungal keratitis. Methods This pre-specified secondary analysis of the Mycotic Ulcer Treatment Trial II (MUTT II) involved patients with filamentous fungal keratitis presenting to Aravind Eye Hospitals in South India. Antifungal susceptibility testing for natamycin and voriconazole was performed on all samples with positive fungal culture results according to Clinical and Laboratory Standards Institute Guidelines. The relationship between MIC and clinical outcomes of best-corrected visual acuity, infiltrate or scar size, corneal perforation, need for therapeutic penetrating keratoplasty, and time to re-epithelialization were assessed. Results We obtained MIC values from 141 patients with fungal keratitis. The most commonly cultured organisms were Aspergillus (46.81%, n = 66) and Fusarium (44.68%, n = 63) species. Overall, there was no association between antifungal MICs and clinical outcomes. Subgroup analysis revealed that among Fusarium-positive cases, higher voriconazole MIC was correlated with worse three-month best-corrected visual acuity (p = 0.03), increased need for therapeutic penetrating keratoplasty (p = 0.04), and time to re-epithelialization (p = 0.03). No significant correlations were found among Aspergillus-positive cases. There were no significant correlations found between natamycin MIC and clinical outcomes among organism subgroups. Conclusions Decreased susceptibility to voriconazole was associated with increased odds of requiring a therapeutic penetrating keratoplasty in Fusarium-positive cases. Susceptibility to natamycin was not associated with any of the measured outcomes.

Abstract Background The whole-genome sequencing (WGS) is becoming an increasingly effective tool for rapid and accurate detection of drug resistance in Mycobacterium tuberculosis complex (MTBC). This approach, however, has still been poorly evaluated on strains from Central and Eastern European countries. The purpose of this study was to assess the performance of WGS against conventional drug susceptibility testing (DST) for the detection of multi-drug resistant (MDR) phenotypes among MTBC clinical strains from Poland and Lithuania. Methods The study included 208 MTBC strains (130 MDR; 78 drug susceptible), recovered from as many tuberculosis patients in Lithuania and Poland between 2018 and 2021. Resistance to rifampicin (RIF) and isoniazid (INH) was assessed by Critical Concentration (CC) and Minimum Inhibitory Concentration (MIC) DST as well as molecular-based techniques, including line-probe assay (LPA) and WGS. The analysis of WGS results was performed using bioinformatic pipeline- and software-based tools. Results The results obtained with the CC DST were more congruent with those by LPA compared to pipeline-based WGS. Software-based tools showed excellent concordance with pipeline-based analysis in prediction of RIF/INH resistance. The RIF-resistant strains demonstrated a relatively homogenous MIC distribution with the mode at the highest tested MIC value. The most frequent RIF-resistance conferring mutation was rpoB S450L. The mode MIC for INH was two-fold higher among double katG and inhA mutants than among single katG mutants. The overall rate of discordant results between all methods was calculated at 5.3%. Three strains had discordant results by both genotypic methods (LPA and pipeline-based WGS), one strain by LPA only, three strains by MIC DST, two strains by both MIC DST and pipeline-based WGS, and the remaining two strains showed discordant results with all three methods, compared to CC DST. Conclusions Considering MIC DST results, current CCs of the first-line anti-TB drugs might be inappropriately high and may need to be revised. Both molecular methods demonstrated 100% specificity, while pipeline-based WGS had slightly lower sensitivity for RIF and INH than LPA, compared to CC DST.

Background The major component of patchouli oil, patchouli alcohol, is used as fixative and has antimicrobial activity. The function of other components, such as α-guaiene, remains unknown. Therefore, this study reports the antifungal activity of α-guaiene isolated from patchouli oil against for pathogenic fungi: Aspergillus niger, Candida albicans ATCC 7102, Microsporum gypseum ATCC 14683, and Trichophyton mentagrophytes ATCC 16404. Methods The material from fraction (249°C-254°C) had the highest α-guaiene. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined using the microdilution technique to evaluate antifungal activity, with n-hexane and medium serving as negative controls, and ketoconazole and fluconazole serving as positive controls. Results The results showed that the MIC value was determined at 45%, 50% for C. albicans, 55%, 60% for A. niger, 50%, 60% for M. gypseum, and 95%, 100% for T. mentagrophytes, respectively. Positive and medium controls demonstrated no microbial growth, whereas negative and growth controls revealed the presence of microorganisms. Fungus resistance to α-guaiene T. mentagrophytes exhibited the highest MIC value. Conclusions Overall, this study reveals that α-guaiene is a promising agent effective against the studied pathogenic fungi.

Background: Terminalia chebula Retz, known as the King of Tibet, is considered a functional food in China, celebrated for its antioxidant, immune-modulating, antibacterial, and anti-inflammatory properties. Chebulinic acid, derived from aqueous extracts of Terminalia chebula Retz, is known for its anti-inflammatory properties. However, its potential as an anti-Helicobacter pylori (HP) agent has not been fully explored. Methods: Herein, we extracted the main compound from Terminalia chebula Retz using a semi-preparative liquid chromatography (LC) system and identified compound 5 as chebulinic acid through Ultra-high performance liquid chromatography-MS/MS (UPLC–MS/MS) and Nuclear Magnetic Resonance (NMR). To evaluate its role, we conducted minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays, scanning electron microscope (SEM) imaging, inhibiting kinetics curves, urea fast test, cell counting kit-8 (CCK-8) assay, western blot analysis, griess reagent system, and molecular docking. Results: Our results showed that chebulinic acid effectively inhibited the growth of the HP strain ATCC 700392, damaged the HP structure, and exhibited selective antimicrobial activity without affecting normal epithelial cells GES-1. Importantly, it suppressed the expression of Cytotoxin-associated gene A (Cag A) protein, a crucial factor in HP infection. Molecular docking analysis predicted a strong affinity (−9.7  kcal/mol) between chebulinic acid and Cag A protein. Conclusion: Overall, our findings suggest that chebulinic acid acts as an antiadhesive agent, disrupting the adhesion of HP to host cells, which is a critical step in HP infection. It also suppresses the Cag A protein. These results highlight the potential of chebulinic acid against HP infections. [ABSTRACT FROM AUTHOR]

The increasing prevalence of microbial infections and antibiotic resistance has sparked interest in investigating the therapeutic potential of silver nanoparticles (AgNPs) as effective antimicrobial agents. The current study seeks to optimize the synthesis of AgNPs using Chrysanthemum morifolium (CM) extract and evaluate their antibacterial activity. Maximum synthesis of CM-AgNPs was achieved using 10 mM of AgNO3 and 20 mg/mL of CM extract at a 6:4 ratio and 3 hr of incubation period at pH 11 and 40°C. The Chrysanthemum morifolium-synthesized silver nanoparticles (CM-AgNPs) displayed a spherical shape, with sizes ranging from 12 to 34 nm. The minimum inhibitory concentration (MIC) against Pseudomonas mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae were 0.0117, 0.0117, 0.0031, and 0.100 mg/mL, respectively. CM-AgNPs demonstrated notable antibiofilm activity of 49.26%, 87.31%, and 66.23% against P. mirabilis, S. aureus, and K. pneumoniae, respectively. These results indicate that CM-AgNPs possess antibacterial properties and hold promise as antimicrobial agents. [ABSTRACT FROM AUTHOR]

Around the world, plants have been used as medicine to ameliorate a broad spectrum of ailments, leveraging their wealth of phytochemicals. Due to their availability and reasonably priced, plant-based medicines have occasionally supplanted synthetic pharmaceuticals. Lindernia ruellioides, locally called as “Thasuih” in Mizoram has been used by indigenous practitioners and traditional healers for treating various ailments. However, there is no scientific validation for this traditional use. Scientific validation at known doses may provide information about its safety and efficacy. Therefore, the present study endeavours to estimate the phytochemical contents and determine the free radical scavenging activity and antibacterial activity of various extracts of The results were evaluated statistically using SPSS (Online) and Graph pad prism (Online).The plant was washed and allowed to shade dried at room temperature and then powdered. It was then subjected to sequential cold maceration using different solvents such as petroleum ether, chloroform, ethanol and distilled water. Phytochemical analysis was carried out using standard procedures to identify the constituents. The ability of the extracts to inhibit the generation of various free radicals was determined by assessing the scavenging activity of 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), 2, 2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and superoxide radicals. Antibacterial activity was determined using disc diffusion method and minimum inhibitory concentration. The results were evaluated statistically using SPSS (Online) and Graph pad prism (Online). The preliminary phytochemical screening disclosed that the plant incorporates an assortment of phytochemicals such as alkaloids, saponins, flavonoids, tannins, steroids, glycosides, phlobatannins and terpenoids. Among the various extracts of L. ruellioides, ethanol extract has the highest total phenolic (327.97 ± 1.77 mg GAE/g of dry extract) and flavonoid contents (264.95 ± 0.71 mg quercetin equivalent/g of dry extract). Different extracts of L. ruellioides when analysed for their scavenging activities showed significant inhibition of DPPH, ABTS and superoxide in a concentration dependent manner. The ethanolic extract showed the highest scavenging activities for DPPH and ABTS with IC50 158.0 ± 4.82 µg/ml and 112.9 ± 6.47 μg/ml respectively. However, aqueous extract was found to possess the highest scavenging activity for superoxide with IC50 135.5 ± 5.02 μg/ml. The different extracts were also found to be active against the test microorganisms, thus, justifying the folkloric use of the plant. [ABSTRACT FROM AUTHOR]

Background and Objectives: Coagulase-negative-Staphylococci (CoNS) are important etiological agent of bacteraemia in newborn babies. Methicillin resistant CoNS infections have only limited treatment options. The antimicrobial susceptibility pattern of Methicillin Resistant CoNS isolates from newborn blood cultures was studied with special reference to MICs of Vancomycin and Teicoplanin. Materials and Methods: The study population included Methicillin Resistant Coagulase Negative Staphylococcal isolates (MRCoNS) from newborn blood cultures, during a one-year period. Minimum inhibitory concentration (MIC) of Vancomycin and Teicoplanin in Methicillin resistant CoNS isolates was determined by macrobroth dilution method as per CLSI guidelines and by automated methods. Results: Coagulase Negative Staphylococci were the etiological agent in 73.7% (n=56) cases of neonatal bacteremia. Methicillin resistance in newborn CoNS was found to be 58.9%. All the MRCoNS isolates had vancomycin and teicoplanin MICs in the susceptible range. There were MRCoNS isolates with MICs in the upper limit of susceptible range for both vancomycin and teicoplanin, which can result in poor clinical response. Conclusion: Continuous large scale multi-centre surveillance studies with special attention to study the MIC pattern of the high-end anti-MRSA agents like vancomycin, teicoplanin, linezolid are to be carried out. This will help the clinicians to judiciously prescribe the antibiotics, which is very essential for antimicrobial stewardship. [ABSTRACT FROM AUTHOR]

Objective: The crucial aim of irrigation solutions used in root canal treatments is the elimination of biofilm which is considered an important virulence factor of Enterococcus faecalis. Essential oils have been investigated to understand their efficacy for biofilm elimination in recent years. This study aimed to evaluate the antimicrobial and antibiofilm effects of Thymus vulgaris essential oils (TEO) and Origanum onites essential oils (OEO) on E. faecalis. Methods: The antimicrobial effectiveness of TEO and OEO against E. faecalis (ATCC 29212) was investigated by broth microdilution method, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The effect of TEO and OEO on preventing biofilm formation was evaluated by measuring biofilm biomass using crystal-violet method, and its effect on biofilm viability was evaluated by determining the number of living cells in the biofilm as colony-forming units. Biofilm viability was analyzed with one-sample t-test with statistical significance accepted as p<0.05. Results: The MIC values of TEO and OEO were determined as 0.078 µL/mL, and MBC values were determined as 0.156 µL/mL for OEO and 0.078 µL/mL for TEO. The percentage inhibition of biofilm formation at MIC value for OEO and TEO was determined as 53.9% and 55.6%, respectively. Both essential oils caused a significant reduction in the number of viable cells within the biofilm. Conclusion: It is concluded that TEO and OEO show high antimicrobial and antibiofilm activity against E. faecalis biofilm. Therefore, these essential oils can be considered an alternative irrigation solution for eliminating resistant root canal infections. [ABSTRACT FROM AUTHOR]

Ngari is a non-salted fermented fish of Manipur and was made by the indigenous people of Manipur North east India. Traditional Knowledge (TK) possessed by different communities is often closely linked to their way of life. The present study tried to document the control of microbial contaminants isolated from Ngari (A fermented fish product) by natural plants products. Two fungi were isolated from the "Ngari" stored at room temperature (150C-200C) for 45 day. Antimicrobial activity of plant extract was done by agar well diffusion method. Of 8 plants extracts, cinnamon ethanolic extract showed antifungal activity with zone of inhibition 55mm and 15mm against green coloured and black coloured fungal isolates, respectively. Mango ethanolic extract showed antifungal activity against black coloured fungal isolate with zone of inhibition 10mm. Mulberry, neen, guava, curry and stem of ginger and termaric extracts did not show any activity against the both fungal isolates. Antibiotic susceptibility pattern of microbial isolates was done by agar disc diffusion method. Ketaconazole showed the best activity against the both fungal i.e (green and black) with zone of inhibition (18mm) followed by Clotrimazole (CC) (12 and 20mm) and Itraconazole (IT) (12 and 17mm), respectively. Nystatin (NS) showed the activity only against the black fungal 13mm. Both fungal isolates were resistant to Amphotericin and Fluconazole. The Cinnamon ethanolic extract exhibited the MIC of 10% w/v against both fungal isolates. The photochemical analysis of cinnamon ethanolic extract was done and showed the presence of alkaloid, tannins and phenols and absence of flavonoid and saponins. It may be suggested from the findings that cinnamon ethanolic extract can be used as a potential source of natural antimicrobial compound to be used as food preservative. Further research is needed for the to identify fungal isolates from Ngari and also to isolate, purify and identify the active antifungal from the cinnamon ethanolic extract. [ABSTRACT FROM AUTHOR]

This present study has been designed to develop an Antifouling agent to minimize the attachment of fouling organisms on the submerged substratum. In order to analyze the leaf extracts of reputable species, such as Ipomoea pescaprae, (sand dune plants) and Sesuvium portulacastrum, Batis maritima (salt marsh), an attempt was undertaken. Methanolic extracts of three plants were screened for antifouling activity against six marine fouling bacteria (Proteus mirabilis, Proteus vulgaris, Pseudomonas sp., Vibrio sp., Staphylococcus aureus, Escherichia coli) using disc diffusion method where the methanolic extract of Ipomea pes caprae exhibited a maximum zone of inhibition (26mm) against Pseudomonas sp. Further, the minimum inhibitory concentration assay was performed to determine the lowest effective concentration to inhibit microbial growth. Hence, the result has suggested Ipomea pes-caprae has a maximum inhibitory percentage (51%) in a lower concentration (100µL) against E. coli. To detect the functional groups in three extracts, FTIR was carried out, where Amine, Secondary Alcohol, Alkane and Amine salt all are commonly present in these three samples. A field study has been designed to evaluate the antifouling efficiency of three samples, where the commercial paint was formulated using methanolic extracts from three different plants. Thus, resulted in Sample-1 (Ipomea pes-caprae) has good bioactivity towards fouling organisms and resulted in less percentage of fouling formation (Wood-10%, Aluminium-22% and Fiber sheet-26%) in this field study. [ABSTRACT FROM AUTHOR]

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Bifidobacteria are commonly used as probiotics in the food industry. The resistance of Bifidobacterium species to antibiotics is closely linked to food safety. However, we still lack a system for the safety evaluation of antibiotic resistance in bifidobacteria, and genus-level microbiological cut-off values remain in use for the determination of phenotypic resistance of Bifidobacterium strains to a given antibiotic. Here, we collected a total of 422 gut-derived bifidobacterial strains isolated from Chinese population and identified their phenotypic resistance profiles against ampicillin, amoxicillin, ciprofloxacin, chloramphenicol, clindamycin, erythromycin, rifampicin, tetracycline, trimethoprim, and vancomycin. Different Bifidobacterium species were found to have varying tolerances to the same antibiotic; therefore, we further established species-specific cut-off values for bifidobacterial species to ten antibiotics. Species-specific rather than genus-specific cut-off values for species belonging to the same taxon were considered more suitable to determine the phenotypic resistance of a Bifidobacterium strain. Moreover, a comprehensive scanning of antibiotic resistance genes in all Bifidobacterium strains tested revealed that the existence of the tetracycline resistance gene tet(W) and the erythromycin/clindamycin resistance gene ErmX is closely related to host phenotypes. Our findings provide guidance and reference values at both phenotype and genotype levels for the safe application of bifidobacteria in the food industry and the development of probiotic resistance evaluation standards. [ABSTRACT FROM AUTHOR]

Simple Summary: Carvacrol, an essential oil compound, has been shown to exhibit antimicrobial activity against pathogens. The aim of this study was to evaluate the post-antibiotic effects (PAE) and post-antibiotic sub-minimum inhibitory concentration (PA-SME) effects of carvacrol on Salmonella Typhimurium at different concentrations (1×, 2×, 4× MIC) and inoculum sizes (106 and 108 CFU/mL). The minimum inhibitory concentration (MIC) of carvacrol was established at 0.6 mg/mL, with a required exposure time of 10 min for bacterial inhibition. The results demonstrated that carvacrol exhibited no PAE at the MIC. However, at the 2× MIC, the PAE was observed to be 2 h for the standard inoculum and 1 h for the high-density inoculum. At 4× MIC, the ECP exceeded 43.5 h for both inocula. Further exposure to sub-MIC carvacrol (0.15 mg/mL) after the post-antibiotic phase resulted in an extended ECP of over 43.5 h. These findings suggest that elevated carvacrol sub-MICs can markedly prolong PA-SME, potentially enabling reduced dosing frequencies, minimised adverse effects and enhanced efficacy in the treatment of infected animals and disinfection of agri-food facilities. Carvacrol is a compound present in essential oils with proven antimicrobial activity against numerous pathogens. We firstly determine the post-antibiotic effect (PAE) of carvacrol (1×, 2×, 4× MIC) and post-antibiotic sub-minimum inhibitory concentration (MIC) effect (1× + 0.25× MIC and 2× + 0.25× MIC) for two concentrations of Salmonella Typhimurium ATCC14028 (106 and 108 CFU/mL). Prior to testing, the minimum concentration and exposure time to achieve the bacterial inhibition (MIC 0.6 mg/mL and 10 min) were determined by broth microdilution and time–kill curve methods, respectively. At the MIC, carvacrol did not generate any PAE. At twice the MIC, the PAE was 2 h with the standard inoculum (106 CFU/mL) and 1 h with the high-density inoculum (108 CFU/mL). At 4× MIC concentrations, the PAE was higher in both cases > 43.5 h. Continuous exposure of post-antibiotic phase bacteria (1× and 2× MIC) to carvacrol at 0.25× MIC (0.15 mg/mL) resulted in an increase in PAE (PA-SME) above 43.5 h with both inocula. These results suggest that the PA-SME of carvacrol for S. Typhimurium can be significantly prolonged by increasing the sub-MICs, which would allow dose spacing, reduce adverse effects and improve its efficacy in the treatment of infected animals and as a disinfectant in agri-food facilities. [ABSTRACT FROM AUTHOR]

Modern cosmetic products, with rich formulations of components, have become an ideal breeding ground for microorganisms. Implementing effective preservative systems is crucial to prevent microbial growth and contamination. Titanium dioxide nanoparticles, a familiar ingredient in cosmetics, can decompose the outer membrane of microbial cells by producing free radicals. Chitosan has shown antimicrobial activities by impairing cell wall integrity by binding to it aiding in the release of cytosolic contents. In line with this, this work was centered on evaluating the antimicrobial efficiency of chitosan-coated titanium dioxide (CS-TiO2) nanoparticles against three bacterial species viz. Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and use them as a self-preservative agent in cosmetic formulations. The growth curve analysis exhibited a dose-dependent delay in bacterial growth. The minimum inhibitory concentration (MIC50) results revealed that the nanoparticles were effective at 31.25μg/ml and 62.5μg/ml concentrations in suppressing S. aureus, P. aeruginosa and E. coli, respectively. The redox imbalance, membrane lipid peroxidation, DNA damage and cell viability analyses showed that the CS-TiO2 nanoparticles could disrupt the membrane leading to reactive oxygen species (ROS) formation and altering the genetic material. Therefore, the conclusions drawn from this research highlight the proficient microbial performance of CS-TiO2, proposing its suitability for incorporation into consumer products, especially cosmetics. As far as the authors are aware, this study is believed to be the first to investigate the potential of CS-TiO2 nanoparticles as a self-preservative. [ABSTRACT FROM AUTHOR]

A recent scientific investigation has shown promising results of selenium nanoparticles (SeNPs) for the anticancer and antimicrobial activities. This study aims to evaluate the effects of PVP SeNPs on bacterial strains, including Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus), Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa). Also, its antitumor activity against the MRC-5 carcinoma cell line. SeNPs were prepared via gamma irradiation using PVP as a capping agent, and their size and morphological structure were determined using HRTEM. The size of the SeNPs ranged from 36 to 66.59 nm. UV–vis spectra confirmed the formation of SeNPs, while FTIR measurement confirmed a change in the PVP structure after adding selenium nanoparticles. The highest effect was reported on HepG2 by an IC50 with a value of 8.87 µg/ml, followed by HeLa, PC3, MCF-7, and Caco2 cell lines, respectively. Furthermore, ZOI reached 36.33 ± 3.05 mm. The best value of the minimum inhibitory concentration (MIC) was 0.313 µg/ml. Scanning electron microscope (SEM) imaging against bacteria showed deformations and distortions in their structures. Transmission electron (TEM) revealed ultrastructure changes in treated bacteria because of the free radicals that made cytotoxicity which confirmed by Electron spin resonance (ESR). [ABSTRACT FROM AUTHOR]

Novel mixed transition metal complexes MnCo2(C4H4O6)36H2O and NiCo2(C4H4O6)36H2O are synthesized using green approach, these tartrate act as a bidentate ligand. For characterisation of complexes elemental analysis, FTIR, XRD, TGA, and SEM with EDAX techniques were used. Analytical data shows that all complexes exhibited 1:1 (metal: ligand) ratio. IR spectral data shows that bidentate ligand coordinate with metal ion as bidentate ligand through the two 'O' atoms. The TGA of the complexes showed good agreement with their suggested formulae. XRD technique shows that all the complexes found to be in polycrystalline nature. SEM shows morphological features and surface characteristics of complexes. The synthesised complexes tested for antibacterial and antifungal activity to check the physiological activity and characterized for its application in the synthesis of heterocyclic compounds as catalysts. [ABSTRACT FROM AUTHOR]

Nowadays, the dilemma of drug resistance to antibacterial strains is of huge concern. Among the bacteria, Escherchia coli (E. coli) is the major pathogen, which is found in human and other animals. It is responsible for variety of severe diseases. A variety of commonly used antibiotics such as amoxicillin, gentamycin, etc and fluid replacement method are the suggested treatments for the infections caused by E. coli. In a study, it was established that the metal-based heterocyclic drugs demonstrated a different mode of action compared to the commonly used heterocyclic antibacterial drugs. Coumarin, an oxaheterocycle, is a privileged scaffold in medicinal chemistry. Metal complexes of coumarin-derived Schiff's bases exhibit a broad range of pharmacological activities. Therefore, in the present review article, we have focused on the synthesis of metal complexes of coumarin derived Schiff's bases as well as their respective Schiff's base ligands and their antibacterial activities against the gram-negative bacterium E. coli. [ABSTRACT FROM AUTHOR]

The novel Schiff bases 3a-d were synthesized by reacting 6-methyl--2-aminobenzothiazole and different substituted benzaldehydes. Afterwards, the obtained Schiff bases were reduced with NaBH4 to form amine compounds 4a-d. In the final step, reaction of the amine with chloroacetyl chloride gave the novel amide derivatives 5a-d. The structures of the all novel synthesized compounds were characterized by FT-IR, ¹H-NMR, 13C-NMR, ESI MS, HETCOR, 2D (¹H-¹H) COSY spectra and elemental analyses. The antimicrobial activities of the novel synthesized compounds, were tested against some Gram-positive and Gram-negative bacterial as well as fungal species and the results were discussed. [ABSTRACT FROM AUTHOR]

There is a focus on using aromatic phosphinous amide as an antibacterial agent against serious multidrug resistant bacterial infections. N-(4-acetylphenyl)-P,P-diphenyl-phosphinous amide and its corresponding thioxophosphinous amide and selenoxo-phosphinous amide were synthesized and designated Ph1, Ph2, and Ph3, respectively. They were structurally identified by single crystal X-ray diffraction, multinuclear NMR spectroscopy, and elemental analysis. Because their antibacterial activities have never been examined, this study aimed to assess their antibacterial activities against both Gram-positive and Gram-negative bacteria as well as readily available standard bacterial strains. Two bacterial isolates were isolated from urine specimens collected from patients with urinary tract infections and designated CS1, and CS2. Phenotypic, biochemical, and molecular approaches were used to identify them. The antibiotic susceptibility/resistance pattern of these isolates was examined by the installed VITEK 2 system. Isolate CS1 is an aerobic Gram-positive, straight rod-shaped, spore forming, occurring singly or in a short chain, whereas isolate CS2 is an aerobic Gram-negative, coccobacilli-shaped, non-spore forming, occurring in pairs or in chains. Both isolates are positive for catalase and oxidase test. According to an examination of the 16S rRNA gene sequence, the isolates CS1 and CS2 have 98% of their similarities with Bacillus and Acinetobacter species, respectively. Isolates CS1 and CS2 are multidrug resistance species. Based on the results of the minimum inhibitory concentration, the standard bacterial strains and isolates CS1 and CS2 showed a wide range in the antibacterial capabilities of the studied phosphinous amides. In comparison to Ph2 and Ph3, Ph1 has the strongest antibacterial activity against all of the tested bacterial species. In conclusion, CS1 and CS2 isolates were identified as novel, multi-drug resistant members of the Bacillus and Acinetobacter genera, respectively. The Ph1 molecule represents a promising new generation of antibiotics with notable antibacterial efficacy against multidrug-resistant Gram-positive and Gram-negative microorganisms. [ABSTRACT FROM AUTHOR]